IGBT 失效分析 IGBT Failure Analysis

1. IGBT 失效分析IGBT FailureAnalysis 李旭/Li Xu(Leo)IFBJ IMM QM

2. 失效分析 Introduction 失效分析的目的是为了维护良好的客户关系，改进产品质量，提高竞争力Failure Analysis isto support customers more effectively during problem solving, and to feedback from field/application for Infineon’s further product development, yield enhancements 失效分析的分析内容是寻找故障点的位置，表征故障现象，确定导致故障的根本原因 Failure Analysis is the localization and characterization of defects 失效分析需要采取多种分析手段，直到找到故障的根本原因，或者直到穷尽所能采取的分析手段 It is necessary to continue until you find the cause or exhaust all tests doing so. 失效分析的挑战：分析周期，分析成本与准确性之间的平衡 Challenge: Do it as fast and accurately as possible

3. 失效分析的分析方法与分析流程FAILURE ANALYSIS-StepByStepForIGBT

4. 失效分析的分析方法与分析流程FAILURE ANALYSIS-StepByStepForIGBT • 1.分析客户反馈的信息 CustomerInformation • 反馈信息表 FARForm • IGBT应用的条件 • 客户观测的故障信息 • 是否已知故障

5. 失效分析的分析方法与分析流程FAILURE ANALYSIS-StepByStepForIGBT • 2.外观检查 VisualInspection • 是否有导热硅脂残留？ Thermalgrease found? • 是否已安装PCB板？ PCB mounted? • 塑料外壳是否被破坏？ Housing damaged? • 是否有烟雾残留物？ Smoke residues found? • 基板是否已被破坏？Base plate damaged? • 模块是否爆炸？ Module exploded? • 模块是否被打开？ Module already opened? • 管脚是否有焊锡残留，是否弯曲，是否脱落？ Solder at pins? Bent pins? Missing pins?

6. 失效分析的分析方法与分析流程FAILURE ANALYSIS-StepByStepForIGBT • 3.电性能分析 ELECTRICAL VERIFICATION • 可编程特性曲线测量 Programmable Curve Tracer • 高压直流电源 HighVoltage DCSupply

7. 失效分析的分析方法与分析流程FAILURE ANALYSIS-StepByStepForIGBT • 4. X射线检测 X-rayInspection • 无损检测 Nondestructive • 检测空焊 IGBTChip soldering, system soldering

8. 失效分析的分析方法与分析流程FAILURE ANALYSIS-StepByStepForIGBT • 5.超声波显微镜检测 UltrasonicMicroscope • 无损检测 Nondestructive • 检测焊层的分层，衬底裂痕 Chip solderingdelamination, substrate crack

9. 失效分析的分析方法与分析流程FAILURE ANALYSIS-StepByStepForIGBT • 6.去除塑料外壳 OpeningHousing/LidRemoval • 破坏性检测 Destructive

10. 失效分析的分析方法与分析流程FAILURE ANALYSIS-StepByStepForIGBT • 7.去除硅胶，去除绝缘钝化层 GelRemovalandPolyimideRemoval • 破坏性检测 Destructive

11. 失效分析的分析方法与分析流程FAILURE ANALYSIS-StepByStepForIGBT • 8.光学显微镜检测 OpticalMicroscope • 无损检测 Nondestructive • Leica, Olympus

12. 失效分析的分析方法与分析流程FAILURE ANALYSIS-StepByStepForIGBT • 9.液晶热点成像分析 FAULT ISOLATIONbyLiquidCrystalAnalysis • 起偏器、检偏器 • 与光学显微镜、curvetracer或者测试机配合使用

13. 失效分析的分析方法与分析流程FAILURE ANALYSIS-StepByStepForIGBT • 10.高端仪器分析-深入芯片内部微米级、纳米级结构 AdvancedFAULT ISOLATION • Delayering 去层 • PhotonEmission Microscope 光子发射显微镜 • SEM and EDX 电子显微镜及特征X光能谱分析 • Cross-section 剖面分析 • FIB 聚焦离子束 • TEM 透射电子显微镜 • SIMS 二次离子质谱

14. 失效分析的分析方法与分析流程FAILURE ANALYSIS-StepByStepForIGBT • 11.分析、总结失效机理 ，确定失效的根本原因 FAILURE MECHANISMS-SUMMARY and REVIEW • 通常存在不止一个故障点 There maybe more than one defect • 哪一个故障点才是失效的根本原因 Which defect is the root cause • 总结失效机理并撰写分析报告 Summary and prepare report

15. IGBT常见失效现象IBGTcommonfailures IGBT 集电极-发射极过压 Collector-Emitter Overvoltage pulse on IGBT IGBT 门极-发射极过压 Gate-Emitter overvoltage IGBT IGBT 过电流脉冲 Overcurrent pulse on IGBT 续流二极管正向过电流，例如浪涌电流 FWDtoohigh current in forward direction RBSOA超出安全工作区RBSOA exceedance for IGBT IGBT过温 Over temperature IGBT 震动产生的故障 Vibration defects 陶瓷衬底裂痕（不恰当的安装过程） Cracked ceramic (inappropriate mounting)

16. IGBT常见失效现象IBGTcommonfailures IGBT 集电极-发射极过压 Collector-Emitter Overvoltage pulse on IGBT

17. IGBT常见失效现象IBGTcommonfailures 集成在门极上的电阻有熔化的现象 Molten areas at the integrated gate resistors IGBT 门极-发射极过压 Gate-Emitter overvoltage IGBT

18. IGBT常见失效现象IBGTcommonfailures IGBT 过电流脉冲 Overcurrent pulse on IGBT

19. IGBT常见失效现象IBGTcommonfailures • 续流二极管正向过电流，例如浪涌电流 • FWDtoohigh current in forward direction, for example surge current I

20. Al layer铝层 Al removed 铝层去除之后 IGBT常见失效现象IBGTcommonfailures • 续流二极管正向过电流，例如浪涌电流 • FWDtoohigh current in forward direction, for example surge current II Typical melting ring around the bond wire 通常会在绑定线的位置周围有熔化现象

21. IGBT常见失效现象IBGTcommonfailures • 续流二极管正向过电流，例如浪涌电流 • FWDtoohigh current in forward direction, for example surge current III Melting tracks ona diode chip(Al removed) 续流二极管：铝层去除之后看到的溶解痕迹

22. IGBT常见失效现象IBGTcommonfailures • RBSOA超安全工作区 RBSOA exceedance for IGBT – turning off an over current I Deep molten spot in the cell field

23. IGBT常见失效现象IBGTcommonfailures • RBSOA超安全工作区 RBSOA exceedance for IGBT – turning off an over current II – Cross Section Cross section: deep molten spot 剖面分析：贯穿芯片的熔洞

24. IGBT常见失效现象IBGTcommonfailures • RBSOA超安全工作区RBSOA exceedance for IGBT – turning off an over current III Deep molten spot with secondary damages

25. IGBT常见失效现象IBGTcommonfailures • IGBT过温 Over temperature IGBT (Al and solder affected) Solder below the IGBT is poured out 底部的焊锡熔化溢出 Large areas of thealuminum layer aremolten, typical beads 大面积的铝层熔化，同时存在熔化后冷凝而产生的小铝珠

26. IGBT常见失效现象IBGTcommonfailures • IGBT过温 Over temperature IGBT (imide layer affected) Bubbles in the imide在涂层上有过温产生的气泡

27. IGBT常见失效现象IBGTcommonfailures • 震动产生的故障 Vibration defects Good bond wires 正常的绑定线 Typical vibration defect: three bond wires cracked one after another.The last wire fused due to the high current. 典型的震动导致的故障点：三根绑定线断裂，最后一根绑定线由于过流而熔断

28. IGBT常见失效现象IBGTcommonfailures • 震动产生的故障 Vibration defects with high power modules Crack at the internal collector terminal 在集电极端子上的裂痕

29. IGBT常见失效现象IBGTcommonfailures • 陶瓷衬底裂痕（不恰当的安装过程）Cracked ceramic (inappropriate mounting) I Crack partially visible around a mounting hole 裂痕环绕安装镙孔

30. IGBT常见失效现象IBGTcommonfailures • 陶瓷衬底裂痕（不恰当的安装过程） Cracked ceramic (inappropriate mounting) II Ultrasonic image of the crack 超声波显微镜观察到的裂痕